Spin-welding of polymeric components having large surface area or non-complementary weld interfaces

Abstract

Friction-weld assemblies and methods of spin-welding are provided, where the components being joined are polymeric components. Designs provided for the polymeric components enable the use of relatively low speeds and pressures to achieve superior friction weld joints between the components. Further, large surface area polymeric components can be successfully friction welded with such designs. In certain variations, at least one polymeric component has a weld surface with a plurality of surface features that are concave (e.g., grooves) or convex. In other variations, the first component in the weld region has a distinct non-complementary shape from the second component, thus creating a progressive advancing weld line that avoids high temperatures that might incur damage to the polymeric component and weld joint. Such component designs additionally provide for improved flash management at the weld joint.

What is claimed is: 
     
       1. An assembly for friction welding, comprising:
 a first polymeric component comprising a first weld surface defining a first shape and comprising a plurality of grooves having an orientation perpendicular to a direction of rotation, wherein the plurality of grooves comprises a first plurality of grooves defining a first length and a second plurality of grooves defining a second length less than the first length; and 
 a second polymeric component comprising a second weld surface defining a second shape, wherein one of the first shape or the second shape is convex, while the other of the first shape or the second shape is concave; wherein the first weld surface and the second weld surface are configured to form a friction weld therebetween when one of the first polymeric component or the second polymeric component remains stationary on a fixed tool, while the other of the first polymeric component or the second polymeric component is rotatable on a rotating tool during friction welding that forms the friction weld joint. 
 
     
     
       2. The assembly of  claim 1 , wherein at least one of the first polymeric component or the second polymeric component is formed from a composite material comprising a thermoplastic polymer and a reinforcement material. 
     
     
       3. The assembly of  claim 1 , wherein each groove of the first plurality of grooves extends from a central region of the first weld surface to an outer perimeter of the first weld surface. 
     
     
       4. The assembly of  claim 1 , wherein the plurality of grooves comprises greater than or equal to about 3 to less than or equal to about 182 grooves on the first weld surface. 
     
     
       5. The assembly of  claim 1 , wherein each groove of the plurality of grooves has a width of greater than or equal to about 0.5 mm to less than or equal to about 3 mm and a depth of greater than or equal to about 0.5 mm to less than or equal to about 3 mm. 
     
     
       6. The assembly of  claim 1 , wherein at least one groove of the plurality of grooves defines a shape on the first weld surface selected from the group consisting of: a triangle, a rectangle, and a quadrilateral. 
     
     
       7. The assembly of  claim 1 , wherein the first shape and the second shape are complementary with respect to one another. 
     
     
       8. The assembly of  claim 1 , wherein the first shape and the second shape are substantially round shapes. 
     
     
       9. A method of spin-welding, comprising:
 rotating a first polymeric component having a first weld surface defining a first shape at a speed of less than or equal to about 3,500 revolutions per minute (rpm), wherein the first weld surface comprises a plurality of grooves having an orientation perpendicular to a direction of rotation and the plurality of grooves comprises a first plurality of grooves defining a first length and a second plurality of grooves defining a second length less than the first length; and 
 contacting the first weld surface of the first polymeric component with a second weld surface defining a second shape of a second polymeric component that is held stationary while the first polymeric component rotates to create a weld joint between the first polymeric component and the second polymeric component, wherein one of the first shape of the first weld surface of the first polymeric component or the second shape of the second weld surface of the second polymeric component is concave, while the other of the first shape of the first weld surface or the second shape of the second weld surface is convex. 
 
     
     
       10. The method of  claim 9 , wherein the contacting occurs under an applied pressure of greater than or equal to about 1 MPa to less than or equal to about 4 MPa. 
     
     
       11. The method of  claim 9 , wherein the rotating and the contacting occur concurrently in either a constant speed spin-welding process or a variable speed spin-welding process. 
     
     
       12. The method of  claim 11 , wherein the rotating occurs at a speed ranging from greater than or equal to about 200 rpm to less than or equal to about 3,500 rpm. 
     
     
       13. The method of  claim 9 , wherein the rotating and the contacting occur concurrently for a duration of greater than or equal to about 1 second to less than or equal to about 10 seconds. 
     
     
       14. An assembly for friction welding, comprising:
 a first polymeric component comprising a first weld surface defining a first shape and comprising a plurality of grooves having an orientation perpendicular to a direction of rotation, wherein the plurality of grooves comprises a first plurality of grooves defining a first length, a second plurality of grooves defining a second length less than the first length, and a third plurality of grooves defining a third length that is less than both the first length and the second length; and 
 a second polymeric component comprising a second weld surface defining a second shape, wherein one of the first shape or the second shape is convex, while the other of the first shape or the second shape is concave; wherein the first weld surface and the second weld surface are configured to form a friction weld therebetween when one of the first polymeric component or the second polymeric component remains stationary on a fixed tool, while the other of the first polymeric component or the second polymeric component is rotatable on a rotating tool during friction welding that forms the friction weld joint.